Do deep-sea polychaete intestinal sulfur compounds contribute to detoxification of metals and hydrogen sulfide ?

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06844
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Nihon University
• Principal Investigator: KOITO Tomoko 日本大学, 生物資源科学部, 講師 (10583148)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 腸管内球晶 / マリアナイトエラゴカイ / 深海熱水噴出域

Outline of Final Research Achievements

This study investigated the hypothesis that Paralvinella hessleri, a deep-sea hydrothermal vent endemic species, forms spherocrystals in their digestive tract cells to detoxify excess sulfur and metals permeating the body from the environment. Intestinal flora of this species and sympatric scale worms were compared, revealing that although both species were similar, spherocrystals were not found in scale worms. In addition, the content of sulfur-containing amino acids was higher than that of this species, while the content of metallic elements was lower. Therefore, it was suggested that intestinal bacteria were not involved in the formation of spherocrystals, and it was found that the metabolism of sulfur and metals was different from that of scale worms. Furthermore, exposure experiments to shallow-water polychaetes suggested that sulfide and metal accumulation mechanisms may exist in the polychaete digestive tract regardless of the habitat.

Free Research Field

海洋生物学

Academic Significance and Societal Importance of the Research Achievements

近年、深海熱水鉱床は鉱物資源の開発対象として注目されている。開発に対する生物影響を明らかにするためには、まずそこに生息する生物の生態を解明し、希少性や特異性の有無を評価することが肝要である。とりわけ熱水噴出域は熱水に由来する化学物質に依存する特異な生態系が形成されている。本研究は、熱水噴出域固有生物を対象とし、その特異性について明らかにした。したがって本研究成果を社会に発信することは生物影響評価の一助になると考えられる。